U.S. patent application number 12/001179 was filed with the patent office on 2008-06-26 for single component one-way clutch.
This patent application is currently assigned to LuK Lamellen und Kupplungsbau Beteiligungs KG. Invention is credited to Michael Davis.
Application Number | 20080149447 12/001179 |
Document ID | / |
Family ID | 39431977 |
Filed Date | 2008-06-26 |
United States Patent
Application |
20080149447 |
Kind Code |
A1 |
Davis; Michael |
June 26, 2008 |
Single component one-way clutch
Abstract
A one-way clutch including a race disposed about an axis for the
clutch and a wedge plate with a plurality of finger elements
extending toward the race and in contact with the race. One of the
plate or race is arranged for rotational connection to a torque
transmitting element in an automotive device and is arranged to
rotate independently of the other of the plate or race for
rotation, with respect to the other of the plate or race, in a
first rotational direction. The plurality of fingers are arranged
to grip the race, to rotationally lock the plate and race, for
relative rotation of the plate or race in a second rotational
direction, opposite the first rotational direction.
Inventors: |
Davis; Michael; (Wooster,
OH) |
Correspondence
Address: |
SIMPSON & SIMPSON, PLLC
5555 MAIN STREET
WILLIAMSVILLE
NY
14221-5406
US
|
Assignee: |
LuK Lamellen und Kupplungsbau
Beteiligungs KG
Buehl
DE
|
Family ID: |
39431977 |
Appl. No.: |
12/001179 |
Filed: |
December 10, 2007 |
Related U.S. Patent Documents
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Application
Number |
Filing Date |
Patent Number |
|
|
60876499 |
Dec 21, 2006 |
|
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Current U.S.
Class: |
192/45.1 |
Current CPC
Class: |
F16H 41/24 20130101;
F16D 41/069 20130101; F16H 2041/246 20130101 |
Class at
Publication: |
192/45.1 |
International
Class: |
F16D 15/00 20060101
F16D015/00 |
Claims
1. A one-way clutch, comprising: a race disposed about an axis for
said clutch; and, a wedge plate with a plurality of finger elements
extending toward said race and in contact with said race, wherein a
one of said wedge plate and race is arranged for rotational
connection to a torque transmitting element in an automotive device
and is arranged to rotate independently of an other of said wedge
plate and race for rotation, with respect to said other of said
wedge plate and race, in a first rotational direction, wherein said
plurality of fingers are arranged to grip said race, to
rotationally lock said wedge plate and race, for rotation of said
one of said wedge plate and race, with respect to said other of
said wedge plate and race, in a second rotational direction,
opposite said first rotational direction.
2. The one-way clutch of claim 1 wherein for at least one finger in
said plurality of fingers a circumferential dimension of a portion
in contact with said race is greater than an axial dimension for
said portion.
3. The one-way clutch of claim 1 wherein said race further
comprises a circumferential surface radially opposite said wedge
plate, and for said rotation of said one of said wedge plate and
race in said first direction, said plurality of fingers are
arranged to slide across said circumferential surface.
4. The one-way clutch of claim 1 wherein said race further
comprises a circumferential surface radially opposite said wedge
plate and for said rotation of said one of said wedge plate and
race in said second direction said plurality of fingers are
arranged to exert a radial force against said circumferential
surface to oppose rotation of said first one of said wedge plate
and race.
5. The one-way clutch of claim 1 wherein said race comprises a
circumferential surface radially opposite said wedge plate and
wherein each finger in said plurality of fingers comprises a
circumferential surface shaped to conform to said circumferential
surface of said race.
6. The one-way clutch of claim 1 further comprising a spacing
element disposed axially through said wedge plate and providing a
solid axial path from one axial end of said clutch to an other
axial end of said clutch.
7. The one-way clutch of claim 1 wherein said race or said wedge
plate is arranged for connection to said torque transmitting
element.
8. A one-way clutch, comprising: a race disposed about an axis for
said clutch; and, a wedge plate with a plurality of finger
elements, wherein said race comprises a circumferential surface
radially opposite said wedge plate, wherein said finger elements
extend radially toward said race, wherein one of said wedge plate
and race is arranged for rotational connection to a torque
transmitting element in an automotive device, and wherein each said
finger element includes a distal end with a circumferential edge
complimentarily shaped with respect to said circumferential
surface.
9. The one-way clutch of claim 8 wherein said circumferential edge
conformably engages said race circumferential surface.
10. The one-way clutch of claim 8 wherein said distal edge is at a
nonuniform radial distance from a longitudinal axis for said wedge
plate when said wedge plate is disengaged from said second
race.
11. The one-way clutch of claim 8 wherein for at least one finger
in said plurality of fingers a circumferential dimension of a
portion in contact with said race is greater than an axial
dimension for said portion.
12. The one-way clutch of claim 8 wherein said one of said wedge
plate and race is arranged to rotate independently of an other of
said wedge plate and race for rotation, with respect to said other
of said wedge plate and race, in a first rotational direction, and
wherein said plurality of fingers are arranged to grip said race,
to rotationally lock said wedge plate and race, for rotation of
said one of said wedge plate and race, with respect to said other
of said wedge plate and race, in a second rotational direction,
opposite said first rotational direction.
13. The one-way clutch of claim 12 wherein said race or said wedge
plate is arranged for connection to said torque transmitting
element.
14. The one-way clutch of claim 8 further comprising a spacing
element disposed axially through said wedge plate and providing a
mechanical path between first and second axial ends for said
clutch.
15. The one-way clutch of claim 14 wherein said spacing element
comprises a plate radially disposed about said axis and having at
least one axially displaced finger, said at least one axially
displaced finger comprising at least a portion of said solid axial
path.
16. A one-way clutch for a stator in a torque converter,
comprising: a hub arranged for rotational connection to a stator
shaft for said stator; and, a wedge plate including a plurality of
finger elements extending radially inward toward said hub, wherein
said wedge plate is arranged for rotational connection to a blade
assembly for said stator, wherein each said finger element includes
a distal end with a circumferential edge complimentarily shaped
with respect to a circumferential surface for said hub, and wherein
said circumferential edge conformably engages said race
circumferential surface.
17. The one-way clutch of claim 16 wherein said distal edge is at a
nonuniform radial distance from a longitudinal axis for said wedge
plate when said wedge plate is disengaged from said hub.
18. The one-way clutch of claim 16 wherein for at least one finger
in said plurality of fingers a circumferential dimension of a
portion in contact with said hub is greater than an axial dimension
for said portion.
19. The one-way clutch of claim 16 wherein said plurality of
fingers are arranged to grip said hub, to rotationally lock said
hub and said outer race for rotation of said outer race in a
rotational direction.
20. The one-way clutch of claim 16 wherein said circumferential
surface comprises a cylindrical surface with a first radius with
respect to said axis and said circumferential edge comprises a
section of a circle with a second radius, with respect to said
axis, substantially equal to said first radius.
21. A one-way clutch, comprising: a race disposed about an axis for
said clutch; and, a wedge plate including a plurality of finger
elements extending radially toward said race, wherein said race
includes a circumferential surface radially opposite said wedge
plate; wherein one of said wedge plate and race is arranged for
rotational connection to a torque transmitting element in an
automotive device, wherein each said finger element includes a
distal end with a circumferential edge complimentarily shaped with
respect to said circumferential surface, wherein said
circumferential edge conformably engages said race circumferential
surface, wherein said distal edge is at a nonuniform radial
distance from a longitudinal axis for said wedge plate when said
wedge plate is disengaged from said race, and wherein for at least
one finger in said plurality of fingers a circumferential dimension
of a portion in contact with said race is greater than an axial
dimension for said portion.
22. A one-way clutch, comprising: a race disposed about an axis for
said clutch; a clutch element radially disposed about said axis;
and, a spacing element disposed axially through said clutch element
plate, wherein one of said clutch element and race is arranged for
rotational connection to a torque transmitting element in an
automotive device and is arranged to rotate independently of an
other of said clutch element and race for rotation, with respect to
said other of said clutch element and race, in a first rotational
direction, wherein said clutch element is arranged to radially
engage said race, to rotationally lock said clutch element and
race, for rotation of said one of said clutch element and race,
with respect to said other of said clutch element and race, in a
second rotational direction, opposite said first rotational
direction, wherein a circumferential extent of said clutch element
in contact with said race is greater than an axial extent of said
clutch element in contact with said race, and wherein said spacing
element provides a mechanical path axially between first and second
axial ends for said clutch.
23. The one-way clutch of claim 22 wherein said spacing element is
arranged to transmit a thrust load between said axial ends.
24. The one-way clutch of claim 22 wherein said spacing element
comprises a plate radially disposed about said axis and having at
least one axially displaced finger, said at least one axially
displaced finger comprising at least a portion of said mechanical
path.
25. The one-way clutch of claim 22 wherein said race comprises a
circumferential surface radially opposite said clutch element,
wherein said clutch element comprises a plurality of finger
elements extending toward said race, wherein each said finger
element includes a distal end with a circumferential edge
complimentarily shaped with respect to said circumferential
surface, and wherein said circumferential edge conformably engages
said race circumferential surface.
Description
CROSS-REFERENCE TO RELATED APPLICATIONS
[0001] This application claims the benefit under 35 U.S.C.
.sctn.119(e) of U.S. Provisional Application No. 60/876,499 filed
on Dec. 21, 2006 which application is incorporated herein by
reference.
FIELD OF THE INVENTION
[0002] The invention relates to improvements in apparatus for
transmitting force. The force can be between a rotary driving unit
(such as the engine of a motor vehicle) and a rotary driven unit
(such as the variable-speed transmission in the motor vehicle), or
the force can be transmitted within a rotary driving unit (such as
the transmission of a motor vehicle). In particular, the invention
relates to a one-way clutch with wedges having a circumferential
dimension greater than an axial dimension and to a radial one-way
clutch with axial spacing.
BACKGROUND OF THE INVENTION
[0003] FIG. 1 illustrates a general block diagram showing the
relationship of the engine 7, torque converter 10, transmission 8,
and differential/axle assembly 9 in a typical vehicle. It is well
known that a torque converter is used to transmit torque from an
engine to a transmission of a motor vehicle.
[0004] The three main components of the torque converter are the
pump 37, turbine 38, and stator 39. The torque converter becomes a
sealed chamber when the pump is welded to cover 11. The cover is
connected to flexplate 41 which is, in turn, bolted to crankshaft
42 of engine 7. The cover can be connected to the flexplate using
lugs or studs welded to the cover. The welded connection between
the pump and cover transmits engine torque to the pump. Therefore,
the pump always rotates at engine speed. The function of the pump
is to use this rotational motion to propel the fluid radially
outward and axially towards the turbine. Therefore, the pump is a
centrifugal pump propelling fluid from a small radial inlet to a
large radial outlet, increasing the energy in the fluid. Pressure
to engage transmission clutches and the torque converter clutch is
supplied by an additional pump in the transmission that is driven
by the pump hub.
[0005] In torque converter 10 a fluid circuit is created by the
pump (sometimes called an impeller), the turbine, and the stator
(sometimes called a reactor). The fluid circuit allows the engine
to continue rotating when the vehicle is stopped, and accelerate
the vehicle when desired by a driver. The torque converter
supplements engine torque through torque ratio, similar to a gear
reduction. Torque ratio is the ratio of output torque to input
torque. Torque ratio is highest at low or no turbine rotational
speed (also called stall). Stall torque ratios are typically within
a range of 1.8-2.2. This means that the output torque of the torque
converter is 1.8-2.2 times greater than the input torque. Output
speed, however, is much lower than input speed, because the turbine
is connected to the output and it is not rotating, but the input is
rotating at engine speed.
[0006] Turbine 38 uses the fluid energy it receives from pump 37 to
propel the vehicle. Turbine shell 22 is connected to turbine hub
19. Turbine hub 19 uses a spline connection to transmit turbine
torque to transmission input shaft 43. The input shaft is connected
to the wheels of the vehicle through gears and shafts in
transmission 8 and axle differential 9. The force of the fluid
impacting the turbine blades is output from the turbine as torque.
Axial thrust bearings 31 support the components from axial forces
imparted by the fluid. When output torque is sufficient to overcome
the inertia of the vehicle at rest, the vehicle begins to move.
[0007] After the fluid energy is converted to torque by the
turbine, there is still some energy left in the fluid. The fluid
exiting from small radial outlet 44 would ordinarily enter the pump
in such a manner as to oppose the rotation of the pump. Stator 39
is used to redirect the fluid to help accelerate the pump, thereby
increasing torque ratio. Stator 39 is connected to stator shaft 45
through one-way clutch 46. The stator shaft is connected to
transmission housing 47 and does not rotate. One-way clutch 46
prevents stator 39 from rotating at low speed ratios (where the
pump is spinning faster than the turbine). Fluid entering stator 39
from turbine outlet 44 is turned by stator blades 48 to enter pump
37 in the direction of rotation.
[0008] The blade inlet and exit angles, the pump and turbine shell
shapes, and the overall diameter of the torque converter influence
its performance. Design parameters include the torque ratio,
efficiency, and ability of the torque converter to absorb engine
torque without allowing the engine to "run away." This occurs if
the torque converter is too small and the pump can't slow the
engine.
[0009] At low speed ratios, the torque converter works well to
allow the engine to rotate while the vehicle is stationary, and to
supplement engine torque for increased performance. At speed ratios
less than 1, the torque converter is less than 100% efficient. The
torque ratio of the torque converter gradually reduces from a high
of about 1.8 to 2.2, to a torque ratio of about 1 as the turbine
rotational speed approaches the pump rotational speed. The speed
ratio when the torque ratio reaches 1 is called the coupling point.
At this point, the fluid entering the stator no longer needs
redirected, and the one way clutch in the stator allows it to
rotate in the same direction as the pump and turbine. Because the
stator is not redirecting the fluid, torque output from the torque
converter is the same as torque input. The entire fluid circuit
will rotate as a unit.
[0010] Peak torque converter efficiency is limited to 92-93% based
on losses in the fluid. Therefore torque converter clutch 49 is
employed to mechanically connect the torque converter input to the
output, improving efficiency to 100%. Clutch piston plate 17 is
hydraulically applied when commanded by the transmission
controller. Piston plate 17 is sealed to turbine hub 19 at its
inner diameter by o-ring 18 and to cover 11 at its outer diameter
by friction material ring 51. These seals create a pressure chamber
and force piston plate 17 into engagement with cover 11. This
mechanical connection bypasses the torque converter fluid
circuit.
[0011] The mechanical connection of torque converter clutch 49
transmits many more engine torsional fluctuations to the
drivetrain. As the drivetrain is basically a spring-mass system,
torsional fluctuations from the engine can excite natural
frequencies of the system. A damper is employed to shift the
drivetrain natural frequencies out of the driving range. The damper
includes springs 15 in series with engine 7 and transmission 8 to
lower the effective spring rate of the system, thereby lowering the
natural frequency.
[0012] Torque converter clutch 49 generally comprises four
components: piston plate 17, cover plates 12 and 16, springs 15,
and flange 13. Cover plates 12 and 16 transmit torque from piston
plate 17 to compression springs 15. Cover plate wings 52 are formed
around springs 15 for axial retention. Torque from piston plate 17
is transmitted to cover plates 12 and 16 through a riveted
connection. Cover plates 12 and 16 impart torque to compression
springs 15 by contact with an edge of a spring window. Both cover
plates work in combination to support the spring on both sides of
the spring center axis. Spring force is transmitted to flange 13 by
contact with a flange spring window edge. Sometimes the flange also
has a rotational tab or slot which engages a portion of the cover
plate to prevent over-compression of the springs during high torque
events. Torque from flange 13 is transmitted to turbine hub 19 and
into transmission input shaft 43.
[0013] Energy absorption can be accomplished through friction,
sometimes called hysteresis, if desired. Hysteresis includes
friction from windup and unwinding of the damper plates, so it is
twice the actual friction torque. The hysteresis package generally
consists of diaphragm (or Belleville) spring 14 which is placed
between flange 13 and one of cover plates 16 to urge flange 13 into
contact with the other cover plate 12. By controlling the amount of
force exerted by diaphragm spring 14, the amount of friction torque
can also be controlled. Typical hysteresis values are in the range
of 10-30 Nm.
[0014] The use of roller clutches, such as clutch 46, also results
in high stress due to the limited contact between the rollers in
the clutch and the components radially bracketing the rollers.
Therefore, the axial length of a roller clutch must be increased,
undesirably increasing the axial space required for a component
housing a roller clutch, for example, stator 39. U.S. Pat. No.
7,040,469 (Shirataki et al.) attempts to address stresses on
retainers for roller clutches, but does not address the problem of
reducing the axial length of the rollers. Sprag one-way clutches
also suffer a similar undesirable increase in axial length for
similar reasons. U.S. Pat. No. 6,953,112 (Miura) addresses problems
associated with asymmetry of a frame for a sprag clutch, but does
not address the problem of reducing the axial length of the clutch.
Thus, roller and sprag one-way clutches increases the cost, weight,
and complexity of stator 39, and subsequently, of torque converter
10. It should be understood that the preceding discussion regarding
one-way clutches is applicable to applications other than a torque
converter.
[0015] Some radial one-way clutches use one or more radially
disposed plates. Unfortunately, thrust loads associated with a
device housing the one-way clutch can cause axial compression of
the plates, impairing the function of the clutch. It is known to
increase the size and strength of end plates to withstand the
loads, but this approach undesirably increases the width, weight,
and cost of the clutch.
[0016] Thus, there is a long-felt need for a one-way clutch
providing a better distribution of stress forces, having a reduced
axial length, and having a means of preventing axial
compression.
BRIEF SUMMARY OF THE INVENTION
[0017] The present invention broadly comprises a one-way clutch
including a race disposed about an axis for the clutch, and a wedge
plate with a plurality of finger elements extending toward the race
and in contact with the race. One of the wedge plate or race is
arranged for rotational connection to a torque transmitting element
in an automotive device and is arranged to rotate independently of
the other of the wedge plate or race for rotation, with respect to
the other of the wedge plate or race, in a first rotational
direction. The plurality of fingers are arranged to grip the race,
to rotationally lock the wedge plate and race, for rotation of the
one of the wedge plate or race, with respect to the other of the
wedge plate or race, in a second rotational direction, opposite the
first rotational direction.
[0018] The race includes a circumferential surface radially
opposite the wedge plate, and for rotation of the one of wedge
plate or race in the first direction the plurality of fingers are
arranged to slide across the circumferential surface. For rotation
of the wedge plate or race in the second direction the plurality of
fingers are arranged to exert a radial force against the
circumferential surface to oppose rotation of the wedge plate or
race. The plurality of fingers is preloaded in the second
direction.
[0019] The race includes a circumferential surface radially
opposite the wedge plate and each finger in the plurality of
fingers includes a circumferential surface shaped to conform to the
circumferential surface of the race. In some aspects, the
circumferential surface for the race includes a cylindrical surface
with a first radius with respect to the axis and the
circumferential surface for each finger includes a section of a
cylindrical surface with a second radius, with respect to the axis,
substantially equal to the first radius. In some aspects, the
one-way clutch includes a spacing element disposed axially through
the wedge plate and providing a mechanical path axially from one
axial end of the clutch to the other axial end of the clutch.
[0020] The present invention also broadly comprises a one-way
clutch including a race disposed about an axis for the clutch and a
wedge plate with a plurality of finger elements. The race includes
a circumferential surface radially opposite the wedge plate, the
finger elements extend radially toward the race, the wedge plate or
race is arranged for rotational connection to a torque transmitting
element in an automotive device, and each finger element includes a
distal end with a circumferential edge complimentarily shaped with
respect to the circumferential surface.
[0021] In some aspects, the distal edge is at a nonuniform radial
distance from a longitudinal axis for the wedge plate when the
wedge plate is disengaged from the race. The circumferential extent
of at least one finger in the plurality of fingers in contact with
the race is greater than an axial extent of the at least one finger
in contact with the race. The wedge plate or race is arranged to
rotate independently of the other of the wedge plate or race for
rotation, with respect to the other of the wedge plate or race, in
a first rotational direction, the plurality of fingers are arranged
to grip the race, to rotationally lock the plate and race, for
rotation of the wedge plate or race in a second relative rotational
direction, opposite the first rotational direction.
[0022] In some aspects, the circumferential surface includes a
cylindrical surface with a first radius with respect to the axis
and the circumferential edge includes a section of a circle with a
second radius, with respect to the axis, substantially equal to the
first radius. In some aspects, the one-way clutch includes a
spacing element disposed axially through the wedge plate and
providing a mechanical axial path from one axial end of the clutch
to the other axial end of the clutch.
[0023] The present invention further broadly comprises a one-way
clutch for a stator in a torque converter, including a hub arranged
for rotational connection to a stator shaft for the stator, and a
wedge plate including a plurality of finger elements extending
radially inward toward the hub. The wedge plate is arranged for
rotational connection to a blade assembly for the stator, each the
finger element includes a distal end with a circumferential edge
complimentarily shaped with respect to a circumferential surface
for the hub, and the circumferential edge conformably engages the
race circumferential surface.
[0024] The present invention broadly comprises a one-way clutch
including a race disposed about an axis for the clutch; a clutch
element radially disposed about the axis; and a spacing element
disposed axially through the clutch element. The plate or race is
arranged for rotational connection to a torque transmitting element
in an automotive device and is arranged to rotate independently of
the other of the plate or race for rotation, with respect to the
other of the plate or race, in a first rotational direction. The
plate is arranged to radially engage the race, to rotationally lock
the plate and race, for rotation of the plate or race, with respect
to the other of the plate or race, in a second rotational
direction, opposite the first rotational direction. A
circumferential extent of the plate in contact with the race is
greater than an axial extent of the plate in contact with the race,
and the spacing element provides a mechanical path axially between
first and second axial ends for the clutch.
[0025] In some aspects, the spacing element is arranged to transmit
a thrust load between the axial ends. In some aspects, the spacing
element includes a plate radially disposed about the axis and
having at least one axially displaced finger, the at least one
axially displaced finger including at least a portion of the
mechanical path. In some aspects, the race includes a
circumferential surface radially opposite the clutch element, the
clutch element includes a plurality of finger elements extending
toward the race, each finger element includes a distal end with a
circumferential edge complimentarily shaped with respect to the
circumferential surface, and the circumferential edge conformably
engages the race circumferential surface.
[0026] It is a general object of the present invention to provide a
one-way clutch having a reduced axial width.
[0027] It is another general object of the present invention to
provide a one-way clutch having a means of preventing axial
compression.
[0028] These and other objects and advantages of the present
invention will be readily appreciable from the following
description of preferred embodiments of the invention and from the
accompanying drawings and claims.
BRIEF DESCRIPTION OF THE DRAWINGS
[0029] The nature and mode of operation of the present invention
will now be more fully described in the following detailed
description of the invention taken with the accompanying drawing
figures, in which:
[0030] FIG. 1 is a general block diagram illustration of power flow
in a motor vehicle, intended to help explain the relationship and
function of a torque converter in the drive train thereof;
[0031] FIG. 2 is a cross-sectional view of a prior art torque
converter, shown secured to an engine of a motor vehicle;
[0032] FIG. 3 is a left view of the torque converter shown in FIG.
2, taken generally along line 3-3 in FIG. 2;
[0033] FIG. 4 is a cross-sectional view of the torque converter
shown in FIGS. 2 and 3, taken generally along line 4-4 in FIG.
3;
[0034] FIG. 5 is a first exploded view of the torque converter
shown in FIG. 2, as shown from the perspective of one viewing the
exploded torque converter from the left;
[0035] FIG. 6 is a second exploded view of the torque converter
shown in FIG. 2, as shown from the perspective of one viewing the
exploded torque converter from the right;
[0036] FIG. 7A is a perspective view of a cylindrical coordinate
system demonstrating spatial terminology used in the present
application;
[0037] FIG. 7B is a perspective view of an object in the
cylindrical coordinate system of FIG. 7A demonstrating spatial
terminology used in the present application;
[0038] FIG. 8 is an exploded front perspective view of a present
invention one-way clutch;
[0039] FIG. 9 is a back view of a wedge plate and inner race shown
in FIG. 8;
[0040] FIG. 10 is a detail of region 10 in FIG. 9 showing the
distal end in two positions;
[0041] FIG. 11 is a cross-sectional view along line 11-11 in FIG.
8; and,
[0042] FIG. 12 is a detail of region 12 in FIG. 11.
DETAILED DESCRIPTION OF THE INVENTION
[0043] At the outset, it should be appreciated that like drawing
numbers on different drawing views identify identical, or
functionally similar, structural elements of the invention. While
the present invention is described with respect to what is
presently considered to be the preferred aspects, it is to be
understood that the invention as claimed is not limited to the
disclosed aspects.
[0044] Furthermore, it is understood that this invention is not
limited to the particular methodology, materials and modifications
described and as such may, of course, vary. It is also understood
that the terminology used herein is for the purpose of describing
particular aspects only, and is not intended to limit the scope of
the present invention, which is limited only by the appended
claims.
[0045] Unless defined otherwise, all technical and scientific terms
used herein have the same meaning as commonly understood to one of
ordinary skill in the art to which this invention belongs. Although
any methods, devices or materials similar or equivalent to those
described herein can be used in the practice or testing of the
invention, the preferred methods, devices, and materials are now
described.
[0046] FIG. 7A is a perspective view of cylindrical coordinate
system 80 demonstrating spatial terminology used in the present
application. The present invention is at least partially described
within the context of a cylindrical coordinate system. System 80
has a longitudinal axis 81, used as the reference for the
directional and spatial terms that follow. The adjectives "axial,"
"radial," and "circumferential" are with respect to an orientation
parallel to axis 81, radius 82 (which is orthogonal to axis 81),
and circumference 83, respectively. The adjectives "axial,"
"radial" and "circumferential" also are regarding orientation
parallel to respective planes. To clarify the disposition of the
various planes, objects 84, 85, and 86 are used. Surface 87 of
object 84 forms an axial plane. That is, axis 81 forms a line along
the surface. Surface 88 of object 85 forms a radial plane. That is,
radius 82 forms a line along the surface. Surface 89 of object 86
forms a circumferential plane. That is, circumference 83 forms a
line along the surface. As a further example, axial movement or
disposition is parallel to axis 81, radial movement or disposition
is parallel to radius 82, and circumferential movement or
disposition is parallel to circumference 83. Rotation is with
respect to axis 81.
[0047] The adverbs "axially," "radially," and "circumferentially"
are with respect to an orientation parallel to axis 81, radius 82,
or circumference 83, respectively. The adverbs "axially,"
"radially," and "circumferentially" also are regarding orientation
parallel to respective planes.
[0048] FIG. 7B is a perspective view of object 90 in cylindrical
coordinate system 80 of FIG. 7A demonstrating spatial terminology
used in the present application. Cylindrical object 90 is
representative of a cylindrical object in a cylindrical coordinate
system and is not intended to limit the present invention in any
manner. Object 90 includes axial surface 91, radial surface 92, and
circumferential surface 93. Surface 91 is part of an axial plane,
surface 92 is part of a radial plane, and surface 93 is part of a
circumferential plane.
[0049] FIG. 8 is an exploded front perspective view of present
invention one-way clutch 100.
[0050] FIG. 9 is a back view of wedge plate 102 and race 106 in
FIG. 8.
[0051] FIG. 10 is a detail of area 10 in FIG. 9 showing distal end
126 in two positions. The following should be viewed in light of
FIGS. 8 through 10. One-way clutch 100 includes at least one wedge
plate 102 at least partially circumferentially disposed about axis
104 for the clutch, and race 106, also at least partially
circumferentially disposed about the axis. One of wedge plate 102
or race 106 is arranged for rotational connection to a torque
transmitting element (not shown) in an automotive device (not
shown) by any means known in the art. By rotationally connected, or
secured, we mean that the plate and the race are connected such
that the respective components rotate together, that is, the
components are fixed with respect to rotation. Rotationally
connecting two components does not necessarily limit relative
movement in other directions. For example, it is possible for two
components that are rotationally connected to have axial movement
with respect to each other via a spline connection. However, it
should be understood that rotational connection does not imply that
movement in other directions is necessarily present. For example,
two components that are rotationally connected can be axially fixed
one to the other. The preceding explanation of rotational
connection is applicable to the discussions infra.
[0052] In some aspects, wedge plate 102 is arranged for connection
to the transmitting element. For example, circumference 108 of
wedge plate 102 is arranged for connection to the torque
transmitting element. In some aspects, the torque transmitting
element is a blade assembly for a stator in a torque converter, for
example, assembly 109, and plate 102, in particular, circumference
108, is arranged for connection to the blade assembly by any means
known in the art, for example, fasteners 110 and openings 112 and
114. Any fasteners known in the art, for example, rivets, can be
used. Then, race 106 is a hub and is rotationally fixed to a
grounded stator shaft (not shown). However, it should be understood
that a present invention clutch is not limited to use with a torque
converter stator and that a present convention clutch can be used
with other torque transmitting elements in other automotive
devices.
[0053] For the discussion that follows and for purposes of
illustration, wedge plates 102 are connected to the torque
transmitting device, unless stated otherwise. However, it should be
understood that race 106, rather than wedge plates 102 can be
connected to the torque transmitting device and that the discussion
infra is generally applicable to the aspects in which race 106 is
connected to the torque transmitting element.
[0054] Each wedge plate includes a plurality of finger elements, or
fingers, 116 extending toward race 106 and in contact with race
106. In FIG. 8, the fingers extend radially inward.
[0055] Wedge plates 102 are arranged to rotate independently of
race 106 for rotation, with respect to race 106, in rotational
direction 120. That is, the wedge plates free wheel for relative
rotation in direction 120. This relative motion can be with respect
to a rotating race or a rotationally fixed race.
[0056] For relative rotation of the wedge plates in direction 122,
opposite direction 120, fingers 116 are arranged to grip race 106,
in particular, circumferential surface 124, to rotationally lock,
or connect, the wedge plates and race 106, as further described
infra. In the configuration shown in the figures, the free-wheel
direction is direction 120 and the locking direction is direction
122. However, it should be understood that clutch 100 is not
limited to this configuration, for example, in some aspects, the
free-wheel and locking directions are reversed from those shown in
the figures.
[0057] Surface 124 is radially opposite the wedge plates and for
rotation of the wedge plates in direction 122, the fingers are
arranged to exert a radial force against surface 124 to oppose
rotation of race 102, also further described infra. In some
aspects, surface 124 is a cylindrical surface. In general, the
wedge plates and fingers are configured in accordance with the
maximum torque expected from the torque transmitting element so
that the fingers not only oppose the rotation of the wedge plates,
the fingers stop the rotation of the wedge plates in the locking
mode direction, for example, direction 122. For relative rotation
of the wedge plates in direction 120, the fingers slidingly engage
race 106 and surface 124. That is, the fingers slide across the
surface without locking with the surface.
[0058] It should be understood that clutch 100 is not limited to a
rotationally fixed race 106 and rotatable wedge plates. In some
aspects, race 106 is arranged for connection to a torque
transmitting element and the wedge plates are fixed. In some
aspects, both the wedge plates and race are rotatable and the
rotation between the torque receiving component(s), which can be
either the wedge plates or the races, and the other component(s) is
a relative rotation. For example, to trigger the lock up mode, the
component(s) connected to the torque transmitting element rotates
more rapidly in the lock up direction than the other
component(s).
[0059] The operation of clutch 100 is now explained in further
detail. In general, the change in position of fingers 116 between
the free-wheel and locking modes is relatively small. Alternately
stated, there is little movement of fingers 116 between the
free-wheel and locking modes. Thus, the amount of lash associated
with a shift between modes is advantageously reduced.
[0060] Fingers 116 include respective distal ends 126 with
circumferential edges 128. Edge 128 is in contact with surface 124.
Edge 128 is complimentarily shaped with respect to surface 124. By
this we mean that edge 128 inversely matches, or mirrors, surface
124. It should be understood that there can be irregularities or
discontinuities in a generally smooth, or continuous, surface 124
and that in general, edge 128 at least matches the continuous
segment of surface 124. Alternately stated, edge 128 conformably
engages surface 124. That is, at least portions of edge 128 are in
full contact with surface 124. In some aspects, surface 124 is a
cylindrical surface with radius 130, and, edge 128 is a section of
a circle with a radius 131 substantially equal to radius 130. That
is, the radii are close enough to enable contact between the
surface and the edge. Radius 131 can be with respect to axis 104 or
with respect to an axis of rotation of the wedge plates, which when
plate 102 is installed in clutch 100, is collinear with axis 104.
In some aspects, edge 128 is part of circumferential surface 132 of
the distal end, surface 132 mirrors surface 124, and surfaces 124
and 132 are respective cylindrical surfaces with substantially the
same radius. For the discussion that follows, surfaces 124 and 132
are presumed to be cylindrical, however, it should be understood
that other shapes for the surfaces are included in the spirit and
scope of the claimed invention.
[0061] To accomplish the sliding engagement in direction 120 and
the locking engagement in direction 122, fingers 116 are preloaded
in direction 122. That is, when the fingers are disengaged from
race 106, for example, when race 106 is removed, the fingers move
at least partially in direction 122 to assume a rest position.
Alternately stated, when the fingers are engaged with race 106, the
fingers are forced in direction 120 and apply a pressure to the
race at least partially directed in direction 122. To illustrate
this point, the approximate position of end 126 when the end is
disengaged from race 106 is shown with a dashed line in FIG. 10. It
should be understood that the change of position shown by the
dashed lines is for purposes of illustration and that other degrees
of movement for end 126 between an engaged and a disengaged
position are possible. That is, other relative positions are within
the spirit and scope of the claimed invention.
[0062] In some aspects, when distal end 126 is disengaged from
surface 124, edge 128 is offset with respect to the circle
described by radius 131. Alternately stated, distal edge 128 is at
a nonuniform radial distance from the longitudinal axis for the
wedge plate when the wedge plate is disengaged from race 106. That
is, the biasing of finger 116 causes end 126 to move from the
position shown in FIG. 10 with solid lines, which is defined by
radius 131, to the position shown with dashed lines. In the dashed
line position, the radial distance between edge 128, or surface
132, and the plate axis varies across circumferential length 134 of
the edge or surface. In general, in clutch 100, edges 128 are
aligned in respective radial planes with respect to axis 104.
Further, the nonuniform radial distance referenced supra presumes
that edges 128 are in a radial plane with respect to the
longitudinal, or rotational, axis for plate 108. In some aspects,
the biasing of the fingers can be implemented by stamping a piece
of material to form the general shape of the fingers, flexing the
fingers to an offset, or biased, position, stamping the distal ends
to form arcuate surfaces 132, and then releasing the fingers.
[0063] Due to the preloading noted supra, surfaces 132 are pushed
in direction 120 when the fingers are engaged with surface 124 and
thus, when the wedge plates turn in direction 120, surfaces 132
slide along surface 124. That is, the sliding motion is a path of
least resistance for the surfaces. However, when the wedge plates
rotate in direction 122, the bias of fingers 116 causes surface 124
to resist the movement of surfaces 132. That is, the engagement of
surfaces 132 and 124 in direction 122 and the resistance of surface
124 causes the generation of radial force 136, which presses
surfaces 132 against surface 124. Alternately stated, the fingers
"jam" against surface 124 to resist further rotation of wedge 102.
In general, increasing the energy applied to rotating the wedge
plates in direction 122, increases force 136, further locking
fingers 116 and race 106.
[0064] For those aspects in which race 106 is connected to the
torque transmitting device, the preceding discussion is applicable,
with the reversal of directions. Specifically, with the
configuration shown, when the race rotates in direction 122 with
respect to the wedge plates, the race free wheels, and when the
race rotates in direction 120, the race and wedge plates lock.
[0065] In some aspects (not shown), the radial configuration of the
wedge plates and race is reversed. That is, the race is disposed
radially outside the wedge plates and the fingers extend radially
outward toward an outer circumference of the plates to engage an
inwardly facing circumferential surface on the race. In general,
the discussion of the wedge plates and race in the description of
FIGS. 8 through 10 is applicable to the preceding configuration
with appropriate adjustment of rotational directions. For example,
in this configuration, either the wedge plates or race can be
connected to the torque transmitting element. In FIG. 8, edge 128
is concave with respect to end 126. In a reverse radial
configuration (fingers extending radially outward), the distal
edges of the fingers are convex with respect to the body of the
finger.
[0066] In some aspects (not shown), the configuration of distal end
126 is reversed. That is, instead of extending circumferentially
from fingers 116 in direction 122 in FIG. 8, distal ends extend
circumferentially from fingers 116 in direction 120. In this case,
the free wheel and locking directions are reversed.
[0067] FIG. 11 is a cross-sectional view along line 11-11 in FIG.
8.
[0068] FIG. 12 is a detail of region 12 in FIG. 11. The following
should be viewed in light of FIGS. 8 through 12. Advantageously,
during rotational lock up of the plates and race, circumferential
dimension 134 of surface 132 of fingers 116 in contact with surface
124 of race 106 is greater than axial dimension 138 of surface 132
in contact with race 106. Alternately stated, the circumferential
extent of the finger elements in contact with the race is greater
than the axial extent of the fingers in contact with the race.
Thus, since the configuration of wedge plates 102 increases the
circumferential extent of contact with the races, the axial extent
of plates 102 is reduced while maintaining the necessary
load-bearing capacity for elements 102. Therefore, the axial extent
of clutch 100 is advantageously reduced.
[0069] In some aspects, a present invention clutch includes a
spacing element. In general, such a clutch includes a race disposed
about an axis for the clutch and a clutch element radially disposed
about the axis. The clutch element or race is arranged for
connection to a torque transmitting element in an automotive
device. The clutch element radially operates to rotationally lock
with the race. The spacing element is disposed axially through the
clutch element to form a mechanical, or solid, path, axially
between axial ends of the clutch. By mechanical path, we mean a
continuous path of solid material. In some aspects, the spacing
element is arranged to transmit a thrust load between the axial
ends.
[0070] For example, in some aspects, the clutch is clutch 100, the
clutch element is plate 102, the race is race 106, and plate 140
includes at least one axial finger, or spacing element, 142. Axial
finger 142 is disposed axially through the wedge plate, for
example, through openings 144. In general, plate 140 is radially
disposed about axis 104. The axial fingers provide a solid axial
path 146 from axial end 148 of clutch 100 to the other axial end,
end 150, of the clutch. That is, the finger forms at least a
portion of the solid, or mechanical, axial path referenced supra.
In some aspects, fingers 142 are arranged to transmit a thrust load
between axial ends 148 and 150. For example, plates 109A and 109B
in conjunction with fingers 142 provide a continuous mechanical
path for thrust loads applied to the clutch.
[0071] In some aspects, clutch 100 is a stator one-way clutch for a
torque converter and thrust loads from bearings (not shown)
radially aligned with fingers 142 apply thrust loads to plates 109A
and 109B and the loads are transmitted through plate 140 and
fingers 142 along path 146.
[0072] Thrust loads along path 146 bypass plates 102, preventing
axial compression of the plates and enabling proper rotation of the
plates. That is, the load is preventing from impinging upon the
wedge plates. In some aspects, plate 140 is formed by stamping and
fingers 142 are punched from the plate, for example, openings 152
in plate 140 are formed when respective fingers 142 are
punched.
[0073] Clutch 100 is shown with five wedge plates 102, however, it
should be understood that clutch 100 is not limited to a specific
number of wedges. For example, clutch 100 can have a single wedge
plate or more than five wedges. Advantageously, the number of wedge
plates used in clutch 100 can be varied according to the torque
expected from the torque transmitting element. For example,
increasing the number of plates increases the torque capacity of
clutch 100 and vice versa. Thus, the number of wedge plates used
can be determined according to the specified torque capacity of the
automotive device using the clutch or manufacturing considerations,
for example, selecting an optimal thickness of the clutch element
with respect to a particular fabricating process. For example, in
some aspects, the clutch elements are formed by stamping and the
thickness of the clutch elements can be determined to accommodate
the stamping equipment used. Specifically, if the clutch is used in
a torque converter stator, the number of clutch elements used in
the clutch could be increased as the power of the engine for the
vehicle housing the torque converter increases and vise versa.
[0074] In some aspects, the inner and outer races, the wedge
plates, or the space plate are formed by stamping.
[0075] Thus, it is seen that the objects of the present invention
are efficiently obtained, although modifications and changes to the
invention should be readily apparent to those having ordinary skill
in the art, which modifications are intended to be within the
spirit and scope of the invention as claimed. It also is understood
that the foregoing description is illustrative of the present
invention and should not be considered as limiting. Therefore,
other embodiments of the present invention are possible without
departing from the spirit and scope of the present invention.
* * * * *